1. Field of the Invention
The present invention relates to an image forming apparatus which includes a function of cleaning a fusing section by passing a sheet on which an image is not formed, before resuming printing after relieving a jam, when a sheet is nipped in a fusing section at the time of an occurrence of the jam.
2. Description of Related Art
In an image forming apparatus such as a copier or a printer using electrophotography which transfers toner images on a sheet and heat-melts and fixes the transferred toner images fusing section cleaning methods have been proposed where, when a sheet may be nipped in a nip section of a fusing section when a jam occurs, a sheet on which an image has not been formed is passed through the fusing section after the jam is settled and before resuming printing, and toner adhered on a surface of the fusing section is transferred to the passed sheet so that the residual toner is removed.
For example, a technique is proposed such as when a printing operation is interrupted by a jam occurrence, etc., if a sheet may be nipped in a nip section of the fusing section at the time, a sheet with a same sheet size or larger and a smaller basis weight than the sheet used in the interrupted printing is chosen from the sheet storing section, and is fed through a fusing roller and pressure roller without forming an image after jam processing, so that residual adhered toner on the rollers are transferred and adhered to the passed sheet and the sheet is ejected to a sheet ejection tray different from the tray where the printed sheet is ejected (For example Japanese Patent Application Laid-open Publication No. 2006-154192, hereinafter referred to as Patent Document 1).
However, with the method of Patent Document 1, sheets which meet the above mentioned size condition and basis weight condition are automatically fed and passed from the sheet storing section. As a result, when size condition and basis weight condition are satisfied, even expensive special sheets such as coated sheets and high quality sheets which a user does not desire to use for cleaning may be used for cleaning.